A Hamilton, Ontario doctor sat in a hot car while connected to monitors to show how quickly a child left in a hot car can be in danger.

Five minutes in, Dr. Crocco was becoming increasingly uncomfortable.“His breathing rate increased just slightly,” local paramedic Michelle Greenspoon observed. “His heart rate increased just slightly, so those are signs that his body is compensating.”Before entering the vehicle, Dr. Crocco explained that extreme temperatures can heat up a car in a very short time. Kids, he said, will quickly start sweating. If they stay in the car much longer, things become incredibly dangerous.“And then you actually stop sweating, and when you stop sweating your body no longer can control the heat and your heat starts to rise,” Dr. Crocco said.

Covered in sweat on a stretcher and clutching a water bottle, Dr. Crocco said if he is affected by this heat on an overcast day, imagine how much worse the experience could be for a child.“Very, very quickly these children’s temperatures are going to rise to a very dangerous level,” he told reporters. “So the message is don't let that happen.”

In a post published on Friday, the Shaughnessy Veterinary Hospital shared a photo of a dog that died after being left in a hot car the same day.

"People obviously still need to be reminded about this, and to me, the best reminder was the picture of the deceased dog lying on our table in the back of the clinic," veterinarian and hospital owner Leah Montgomery told Global News, speaking about the difficult decision of whether or not to post the photo.

"[I]f that doesn’t hit home to people, I don’t know what else is going to."

Two recent incidents with children in hot cars in the province of Ontario. In Burlington, a three year old child was found dead in a hot car in a parking lot.

In Hamilton, a 6 year old in the car of a parent's adult friend was seen in a locked car and the child was noticed by a couple in a Walmart parking lot. Before the man could use his tools to break into the car, the woman asked the boy to unlock the car--which he managed to do.

The charges come on the same day as Halton police broke the window of a vehicle to rescue a 5-month-old baby locked inside. The car was parked in the Milton Crossroads plaza.

The child was overheated, but declared stable by Halton paramedics.

Last week and also this week, I have seen small dogs left in cars in parking lots. Southern Ontario is having a week of temperatures with humidity making it seem like 33-35C in some cases and sometimes the winds are not gusty even if the car windows have been left open.

Don't leave people or pets in hot vehicles unattended during hot weather. Paved parking will amplify the effects of heat as the sunshine's power is absorbed by the asphalt.

Many times, when a child died, there had been a change in the day’s routine, Diamond says. For example, a parent who wouldn’t normally be responsible for day-care drop-off might have been given that task that day. Because our brains recognize a pattern for the day, this parent would drive to work as usual, even though the baby was along for the ride. And unless there was an external cue, such as seeing the diaper bag or hearing the baby, the parent’s brain would continue on autopilot and could even create a false memory that the child is safely at day care, Diamond found. Sleep deprivation and stress can also increase the potential for a working-memory failure.

It seems that the father may be suffering from a form of post-traumatic stress syndrome:

Defence attorney Brian Greenspan said Pennell's actions have already devastated him. In a statement to the court, Jennifer said Pennell cried constantly for months following Wyatt's death.

She also said he has lost weight and has sleep issues and frequent disturbing flashbacks.

"He struggles to make it through the days, but he continues to go to work and provide for his family. He is haunted by what he has done. He knows why our son is no longer here and it is torture," said Jennifer.